The present technique relates to a data correction method for a fine particle measurement device and a fine particle measurement device. More specifically, the present technique relates to, e.g., a data correction method for a fine particle measurement device for correcting measurement error caused by variation of flow positions of fine particles in a channel formed in a flow cell, a microchip, and the like.
A fine particle measurement device is known, which forms a laminar flow (which is also referred to as a sheath flow) including fine particles in a channel formed in a flow cell, a microchip, and the like, emits light onto the fine particles in the laminar flow, and detects fluorescence and scattered light generated from the fine particles. For example, a flow cytometer can measure and analyze the optical property of the fine particles such as cells and beads on the basis of the intensity or the spectrum of the fluorescence or the scattered light detected.
In the fine particle measurement device, the laminar flow is formed so that the fine particles flow substantially in the center of the channel, but the flow position of each fine particle in the channel varies, and therefore, measurement error caused by this variation is problematic. The variation of the flow position of the fine particles in the channel and the measurement error caused by this variation are especially large when the flow rate of the sample liquid laminar flow including the fine particles in the laminar flow is configured to be more than the flow rate of the sheath fluid laminar flow in order to reduce the time it takes to perform the measurement.
When the flow position in the channel varies among the fine particles, the relationship in the positions in terms of optics between the fine particles and the light emission system for the fine particles and the detection system of the fluorescence and the scattered light generated from the fine particles is different among the fine particles. As a result, measurement error caused by the deviation of the optical position occurs in the intensity and the spectrum of the fluorescence and the scattered light detected in each fine particle.
Patent Document 1 and Patent Document 2 disclose a technique for suppressing the measurement error caused by variation of the flow position of the fine particles. In the fluid particle analysis device described in Patent Document 1, detection light (scattered light) retrieved via an optical divider from forward scattered light, side scattered light or backward scattered light is detected by a quadrant photodiode, an area CCD, and the like. Then, the deviation of the positions between the center of the excitation light and the center of the sheath flow is detected from the detection position, and the position of the flow cell is adjusted so that this deviation of the positions stays within a predetermined range. Patent Document 2 describes a technique for detecting position information about fine particles by using polarization angle change that occurs in the scattered light generated from fine particles and adjusting the focal position of the excitation light or the position of the flow cell.